Date: Sun, 7 Feb 1999 15:44:01 PST From: Bill Fenner <fenner@parc.xerox.com> To: Dag-Erling Smorgrav <des@flood.ping.uio.no> Cc: wpaul@FreeBSD.ORG, nsouch@FreeBSD.ORG, hackers@FreeBSD.ORG Subject: Re: Regarding tcpdump and plip Message-ID: <199902072344.PAA06579@mango.parc.xerox.com> In-Reply-To: Your message of "Sun, 07 Feb 1999 15:16:13 PST." <86n22pg5z6.fsf@niobe.ewox.org>
next in thread | previous in thread | raw e-mail | index | archive | help
Here are some diffs that I wrote ages ago for lpt.c, but never
committed because nobody volunteered to test them. They at least
demonstrate what tcpdump wants (an int, in host byte order, with
AF_INET in it). You could also look at if_sl.c, if_loop.c, etc.
Bill
Index: lpt.c
===================================================================
RCS file: /home/ncvs/src/sys/i386/isa/lpt.c,v
retrieving revision 1.72
diff -u -r1.72 lpt.c
--- lpt.c 1998/12/10 01:42:32 1.72
+++ lpt.c 1999/02/07 23:39:10
@@ -876,7 +876,7 @@
printf("lp%d: TCP/IP capable interface\n", unit);
#if NBPFILTER > 0
- bpfattach(ifp, DLT_NULL, LPIPHDRLEN);
+ bpfattach(ifp, DLT_NULL, sizeof(u_int));
#endif
}
/*
@@ -1098,6 +1098,25 @@
sc->sc_if.if_ibytes += len;
top = m_devget(sc->sc_ifbuf + CLPIPHDRLEN, len, 0, &sc->sc_if, 0);
if (top) {
+#if NBPFILTER > 0
+ if (sc->sc_if.if_bpf) {
+ /*
+ * We need to prepend the address family as
+ * a four byte field. Cons up a dummy header
+ * to pacify bpf. This is safe because bpf
+ * will only read from the mbuf (i.e., it won't
+ * try to free it or keep a pointer to it).
+ */
+ struct mbuf m0;
+ u_int af = AF_INET;
+
+ m0.m_next = top;
+ m0.m_len = 4;
+ m0.m_data = (char *)⁡
+
+ bpf_mtap(ifp, &m0);
+ }
+#endif
IF_ENQUEUE(&ipintrq, top);
schednetisr(NETISR_IP);
}
@@ -1142,16 +1161,30 @@
IF_DROP(&ipintrq);
goto done;
}
-#if NBPFILTER > 0
- if (sc->sc_if.if_bpf) {
- bpf_tap(&sc->sc_if, sc->sc_ifbuf, len);
- }
-#endif
len -= LPIPHDRLEN;
sc->sc_if.if_ipackets++;
sc->sc_if.if_ibytes += len;
top = m_devget(sc->sc_ifbuf + LPIPHDRLEN, len, 0, &sc->sc_if, 0);
if (top) {
+#if NBPFILTER > 0
+ if (sc->sc_if.if_bpf) {
+ /*
+ * We need to prepend the address family as
+ * a four byte field. Cons up a dummy header
+ * to pacify bpf. This is safe because bpf
+ * will only read from the mbuf (i.e., it won't
+ * try to free it or keep a pointer to it).
+ */
+ struct mbuf m0;
+ u_int af = AF_INET;
+
+ m0.m_next = top;
+ m0.m_len = 4;
+ m0.m_data = (char *)⁡
+
+ bpf_mtap(ifp, &m0);
+ }
+#endif
IF_ENQUEUE(&ipintrq, top);
schednetisr(NETISR_IP);
}
@@ -1221,6 +1254,26 @@
/* Suspend (on laptops) or receive-errors might have taken us offline */
outb(lpt_ctrl_port, LPC_ENA);
+#if NBPFILTER > 0
+ if (ifp->if_bpf) {
+ /*
+ * We need to prepend the address family as
+ * a four byte field. Cons up a dummy header
+ * to pacify bpf. This is safe because bpf
+ * will only read from the mbuf (i.e., it won't
+ * try to free it or keep a pointer to it).
+ */
+ struct mbuf m0;
+ u_int af = AF_INET;
+
+ m0.m_next = m;
+ m0.m_len = 4;
+ m0.m_data = (char *)⁡
+
+ bpf_mtap(ifp, &m0);
+ }
+#endif
+
if (ifp->if_flags & IFF_LINK0) {
if (!(inb(lpt_stat_port) & CLPIP_SHAKE)) {
@@ -1330,25 +1383,6 @@
} else {
ifp->if_opackets++;
ifp->if_obytes += m->m_pkthdr.len;
-#if NBPFILTER > 0
- if (ifp->if_bpf) {
- /*
- * We need to prepend the packet type as
- * a two byte field. Cons up a dummy header
- * to pacify bpf. This is safe because bpf
- * will only read from the mbuf (i.e., it won't
- * try to free it or keep a pointer to it).
- */
- struct mbuf m0;
- u_short hdr = 0x800;
-
- m0.m_next = m;
- m0.m_len = 2;
- m0.m_data = (char *)&hdr;
-
- bpf_mtap(ifp, &m0);
- }
-#endif
}
m_freem(m);
To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-hackers" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199902072344.PAA06579>